M5.Axp use Wire1 as I2C to communicate on ports 21 and 22, as described in https://github.com/m5stack/M5StickC/blob/master/src/AXP192.cpp.

Because of that, any commands as Wire1.beginTransmission, result in error. The M5.Axp, use Write1Byte to send information (and is not validating if was successful, because of that, I haven't any log).

void AXP192::Write1Byte( uint8_t Addr ,  uint8_t Data )
{
    Wire1.beginTransmission(0x34);
    Wire1.write(Addr);
    Wire1.write(Data);
    Wire1.endTransmission();
}

The I2C Axp Address (0x34) isn't ready in one of my M5Stick-C. If you have any idea, please let me know -- I'm really trying anything to get AXP fully functional again, because I can't see anything (in display) without Axp.

In my code above, you will see a test in endTransmission as mencioned to test the result.

Thank you by all your attention. Please let me know if you have any idea.

If anyone have any idea about how to procedure, I'll appreciate!
Thank you in advance and thank you for share with us.

But if it is a solution, I'll do that! If you can tell me the how much time, I really appreciate. Please, let me ask you something, If you could create a Youtube video showing that solution, I belive it will be amazing. Many M5Stick-C buyers will go to face this same problem and now have no reference to follow.

Thank you again by your disposition to share how to solve the problem :)

M5StickC initializing...OK
M5StickC I2C Tester
Millis: 4057 - Scanning Address
Port: 1 - Found: 0x34
Port: 1 - Found: 0x51
Port: 1 - Found: 0x68
Finished, total: 3 devices!

When I run the same software in a unit with problem, I obtain the bellow result:

M5StickC I2C Tester
Millis: 4047 - Scanning Address
Port: 1 - Found: 0x51
Port: 1 - Found: 0x68
Finished, total: 2 devices!

The AXP I2C address (0x34) is not found. Are anyone knows how to solve that?

@m5stack please help me.
@lukasmaximus I see you have a big knowloged about M5Stack products. Are you know something about that? Could you help me, please?

My I2C tester code:

#include <M5StickC.h>

void setup()
{
  M5.begin();
  Serial.println("M5StickC I2C Tester");
  Wire.begin();
  Wire1.begin();
  delay(3000);
}

byte checkResult(byte error, byte address, byte wirePort)
{
  if (error == 0)
  {
    Serial.print("Port: ");
    Serial.print(wirePort);
    Serial.print(" - Found: 0x");
    Serial.println(address, HEX);
    return 1;
  }
  return 0;
}

void loop()
{
  byte address = 1;
  byte devices = 0;

  Serial.print("Millis: ");
  Serial.print(millis());
  Serial.println(" - Scanning Address");

  for (; address < 127; address++)
  {
    Wire.beginTransmission(address);
    Wire1.beginTransmission(address);
    devices += checkResult(Wire.endTransmission(), address, 0);
    devices += checkResult(Wire1.endTransmission(), address, 1);
    delay(10);
  }
  Serial.print("Finished, total: ");
  Serial.print(devices);
  Serial.println(" devices!\n\n");
  delay(5000);
}

M5StickC initializing...OK
M5StickC I2C Tester
Millis: 4041 - Scanning Address
Finished, total: 0 devices!

I made the code bellow to scan:

#include <M5StickC.h>

void setup() 
{
  M5.begin();
  Serial.println("M5StickC I2C Tester"); 
  Wire.begin();
  delay(3000);
}

void loop() 
{
  byte address, error;
  byte devices = 0;
  
  Serial.print("Millis: ");
  Serial.print(millis());
  Serial.println(" - Scanning Address");
  
  for(address = 1; address < 127; address++ ) 
  {
    Wire.beginTransmission(address);
    error = Wire.endTransmission();
    if (error==0)
    {
      devices++;
      Serial.print("- Found: 0x");
      Serial.println(address, HEX);
    }

    delay(10);
  }
  Serial.print("Finished, total: ");
  Serial.print(devices);
  Serial.println(" devices!\n\n");
  delay(5000);
}

What you believe I need to do? Because my hardware are entirely new and I don't used any pins for nothing.

I bought more U$ 400.00 in hardware from M5Stack and I'm very preocupated if something like that happens to others. Because the logistic process to repair could be inviable (country rules: Brazil).

If you have any insight to solve that, I'll be appreciate. Thank you in advance.

@m5stack please, help me!!

OSError: I2C bus error (-1)

The AXP192 PMIC is controlled via I2C, if the bus isn't working maybe the LDO3/2 isn't enabled. Start with a I2C scan to see if a device with address 52 (thats the AXP192) is available. More code is in the post linked above.

NameError: name 'lcd' isn't defined

Something went wrong with the initialization of the lcd python module. Maybe the wrong version is included?

I tried the Factory Test Firmware, put my own firmware and nothing. I tried to short-cut pins BAT+GND, and insert the USB-C cable, but the screen does not lit (I waited for 2 secs), after that, I removed the short-cut (I'm afraid about fry my device).

How much time are you waited in this short-cut? Anyone can help us??

EDIT: in my firmware I used the default settings as bellow

void setup(void)
{
    M5.begin(true, true, true);
    M5.Lcd.fillScreen(WHITE);
    M5.Axp.ScreenBreath(15); // 7-15
}

Anyways, the screen isn't show anything including in the Factory Test Firmware. When I try to used UIFlow, show me an error when connect via I2C to AXP. Are anyone experienced something like that?

@m5stack can you help me, please?

EDIT2: More information when I run UIFlow (terminal info):

--- Miniterm on /dev/cu.usbserial-3D527252B4  115200,8,N,1 ---
--- Quit: Ctrl+C | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
␛[0;32mI (9) boot: ESP-IDF v3.3-beta1-696-gc4c54ce07 2nd stage bootloader␛[0m
␛[0;32mI (9) boot: compile time 19:32:01␛[0m
␛[0;32mI (9) boot: Enabling RNG early entropy source...␛[0m
␛[0;32mI (14) boot: SPI Speed      : 80MHz␛[0m
␛[0;32mI (18) boot: SPI Mode       : DIO␛[0m
␛[0;32mI (22) boot: SPI Flash Size : 4MB␛[0m
␛[0;32mI (26) boot: Partition Table:␛[0m
␛[0;32mI (29) boot: ## Label            Usage          Type ST Offset   Length␛[0m
␛[0;32mI (37) boot:  0 nvs              WiFi data        01 02 00009000 00006000␛[0m
␛[0;32mI (44) boot:  1 phy_init         RF data          01 01 0000f000 00001000␛[0m
␛[0;32mI (52) boot:  2 factory          factory app      00 00 00010000 001f0000␛[0m
␛[0;32mI (59) boot:  3 internalfs       Unknown data     01 81 00200000 00200000␛[0m
␛[0;32mI (67) boot: End of partition table␛[0m
␛[0;32mI (71) esp_image: segment 0: paddr=0x00010020 vaddr=0x3f400020 size=0xe95ac (955820) map␛[0m
␛[0;32mI (354) esp_image: segment 1: paddr=0x000f95d4 vaddr=0x3ffbdb60 size=0x034dc ( 13532) load␛[0m
␛[0;32mI (359) esp_image: segment 2: paddr=0x000fcab8 vaddr=0x40080000 size=0x00400 (  1024) load␛[0m
␛[0;32mI (361) esp_image: segment 3: paddr=0x000fcec0 vaddr=0x40080400 size=0x03150 ( 12624) load␛[0m
␛[0;32mI (374) esp_image: segment 4: paddr=0x00100018 vaddr=0x400d0018 size=0xdcac4 (903876) map␛[0m
␛[0;32mI (638) esp_image: segment 5: paddr=0x001dcae4 vaddr=0x40083550 size=0x12a98 ( 76440) load␛[0m
␛[0;32mI (664) esp_image: segment 6: paddr=0x001ef584 vaddr=0x400c0000 size=0x00064 (   100) load␛[0m
␛[0;32mI (664) esp_image: segment 7: paddr=0x001ef5f0 vaddr=0x50000000 size=0x00808 (  2056) load␛[0m
␛[0;32mI (685) boot: Loaded app from partition at offset 0x10000␛[0m
␛[0;32mI (685) boot: Disabling RNG early entropy source...␛[0m
␛[0;32mI (685) cpu_start: Pro cpu up.␛[0m
␛[0;32mI (689) cpu_start: Application information:␛[0m
␛[0;32mI (694) cpu_start: Compile time:     Dec 27 2019 19:32:08␛[0m
␛[0;32mI (700) cpu_start: ELF file SHA256:  0000000000000000...␛[0m
␛[0;32mI (706) cpu_start: ESP-IDF:          v3.3-beta1-696-gc4c54ce07␛[0m
␛[0;32mI (712) cpu_start: Starting app cpu, entry point is 0x400836e4␛[0m
␛[0;32mI (0) cpu_start: App cpu up.␛[0m
␛[0;32mI (723) heap_init: Initializing. RAM available for dynamic allocation:␛[0m
␛[0;32mI (730) heap_init: At 3FFAE6E0 len 0000F480 (61 KiB): DRAM␛[0m
␛[0;32mI (736) heap_init: At 3FFCB2D8 len 00014D28 (83 KiB): DRAM␛[0m
␛[0;32mI (742) heap_init: At 3FFE0440 len 00003AE0 (14 KiB): D/IRAM␛[0m
␛[0;32mI (748) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM␛[0m
␛[0;32mI (755) heap_init: At 40095FE8 len 0000A018 (40 KiB): IRAM␛[0m
␛[0;32mI (761) cpu_start: Pro cpu start user code␛[0m
␛[0;32mI (107) cpu_start: Starting scheduler on PRO CPU.␛[0m
␛[0;32mI (0) cpu_start: Starting scheduler on APP CPU.␛[0m

Internal FS (FatFS): Mounted on partition 'internalfs' [size: 2097152; Flash address: 0x200000]
----------------
Filesystem size: 2035712 B
           Used: 479232 B
           Free: 1556480 B
----------------
Traceback (most recent call last):
  File "boot.py", line 4, in <module>
  File "flowlib/uiflow.py", line 1, in <module>
  File "flowlib/m5stack.py", line 14, in <module>
  File "flowlib/hw/axp192.py", line 28, in powerAll
  File "flowlib/hw/axp192.py", line 125, in _regChar
OSError: I2C bus error (-1)
Traceback (most recent call last):
  File "main.py", line 1, in <module>
NameError: name 'lcd' isn't defined
MicroPython v1.11-316-gca0d8a0a5 on 2019-12-27; ESP32 module with ESP32
Type "help()" for more information.
>>> 

1. Erase and then flash UIFlow with M5Burner.
2. Disconnect USB from PC
3. Press PWR Button 6 sec to turn stick off.
4. Connect M5Stick to PC again

[env:m5stack-core-esp32]
platform = espressif32
board = m5stack-core-esp32
framework = arduino
board_build.flash_mode = qio
board_build.f_flash = 80000000L
board_build.partitions = no_ota.csv
upload_speed = 750000

I've tried with the BAT + GND solution but with no success :(
Tried erasing and loading m5stick_factorytest firmware.
Tried erasing and loading uiflow-v1.4.3 firmware with m5burner:

esptool.py v2.5.0
Serial port COM4
Connecting....
Detecting chip type... ESP32
Chip is ESP32-PICO-D4 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, Embedded Flash, VRef calibration in efuse
MAC: d8:a0:1d:50:51:d8
Uploading stub...
Running stub...
Stub running...
Erasing flash (this may take a while)...
Chip erase completed successfully in 2.1s
Hard resetting via RTS pin...
Finished

Command:
--chip esp32 --port COM4 --baud 750000 --before default_reset --after no_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x10000 application_0x10000.bin 0x1000 bootloader_0x1000.bin 0x200000 fatfsImg_0x200000.img 0x8000 partitions_0x8000.bin 0xf000 phy_init_data_0xf000.bin
===================================================****
esptool.py v2.5.0
Serial port COM4
Connecting....
Chip is ESP32-PICO-D4 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, Embedded Flash, VRef calibration in efuse
MAC: d8:a0:1d:50:51:d8
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 750000
Changed.
Configuring flash size...
Auto-detected Flash size: 4MB
Compressed 1965600 bytes to 1378389...

Writing at 0x00010000... (1 %)
...
Writing at 0x0021c000... (100 %)
Wrote 2097152 bytes (125780 compressed) at 0x00200000 in 2.5 seconds (effective 6809.0 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 122...

Writing at 0x00008000... (100 %)
Wrote 3072 bytes (122 compressed) at 0x00008000 in 0.0 seconds (effective 1540.8 kbit/s)...
Hash of data verified.
Compressed 144 bytes to 69...

Writing at 0x0000f000... (100 %)
Wrote 144 bytes (69 compressed) at 0x0000f000 in 0.0 seconds (effective 72.2 kbit/s)...
Hash of data verified.

Leaving...
Staying in bootloader.

Stick is working, but blank screen.
Maybe I've messed up partition table or something... I've not connected anything more than the USB-C cable to the computer and shorted the GND-BAT pins to try to solve the problem, so couldn't be a hardware problem...

Short 'BAT' with 'GND', then connect USB cable to power on.
and upload the test code of Arduino.

and the screen is working again!

Thank you for your answers

I hope this works for someone else

I tried a wipe with M5burner and upload the latest uiflow, not work

Another wipe with M5burner and upload the test code with arduino, the led works with the side button

Still geting the black screen

e.e

Yes I have the orange one, M5StickC
I will try the M5burner to wipe it

I never used UIflow by now, only arduino ide

I hope that works :)

Thanks

There is a similar question below.
http://forum.m5stack.com/topic/1454/m5stick-oled-cant-turn-on

This is a different stick.
There are 3 sticks available.
M5Stick (gray) no longer supported in UIFLOW.
M5StickC (Orange) Current model
M5StickV (Blue) Not supported in UIFlow due to its AI Features.

When writing to the M5StickC Make sure that you have selected the correct board as it works differently to the M5Stack.

Try using M5Burner to wipe the StickC and install firmware 1.4 for M5Stick